diff options
Diffstat (limited to 'src/env.c')
| -rw-r--r-- | src/env.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/src/env.c b/src/env.c new file mode 100644 index 00000000..20d5fb8b --- /dev/null +++ b/src/env.c @@ -0,0 +1,159 @@ +/* env - run a program in a modified environment + Copyright (C) 1986-2012 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* Richard Mlynarik and David MacKenzie */ + +#include <config.h> +#include <stdio.h> +#include <sys/types.h> +#include <getopt.h> + +#include "system.h" +#include "error.h" +#include "quote.h" + +/* The official name of this program (e.g., no 'g' prefix). */ +#define PROGRAM_NAME "env" + +#define AUTHORS \ + proper_name ("Richard Mlynarik"), \ + proper_name ("David MacKenzie") + +static struct option const longopts[] = +{ + {"ignore-environment", no_argument, NULL, 'i'}, + {"null", no_argument, NULL, '0'}, + {"unset", required_argument, NULL, 'u'}, + {GETOPT_HELP_OPTION_DECL}, + {GETOPT_VERSION_OPTION_DECL}, + {NULL, 0, NULL, 0} +}; + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + emit_try_help (); + else + { + printf (_("\ +Usage: %s [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...]\n"), + program_name); + fputs (_("\ +Set each NAME to VALUE in the environment and run COMMAND.\n\ +\n\ + -i, --ignore-environment start with an empty environment\n\ + -0, --null end each output line with 0 byte rather than newline\n\ + -u, --unset=NAME remove variable from the environment\n\ +"), stdout); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + fputs (_("\ +\n\ +A mere - implies -i. If no COMMAND, print the resulting environment.\n\ +"), stdout); + emit_ancillary_info (); + } + exit (status); +} + +int +main (int argc, char **argv) +{ + int optc; + bool ignore_environment = false; + bool opt_nul_terminate_output = false; + + initialize_main (&argc, &argv); + set_program_name (argv[0]); + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + initialize_exit_failure (EXIT_CANCELED); + atexit (close_stdout); + + while ((optc = getopt_long (argc, argv, "+iu:0", longopts, NULL)) != -1) + { + switch (optc) + { + case 'i': + ignore_environment = true; + break; + case 'u': + break; + case '0': + opt_nul_terminate_output = true; + break; + case_GETOPT_HELP_CHAR; + case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); + default: + usage (EXIT_CANCELED); + } + } + + if (optind < argc && STREQ (argv[optind], "-")) + ignore_environment = true; + + if (ignore_environment) + { + static char *dummy_environ[] = { NULL }; + environ = dummy_environ; + } + + optind = 0; /* Force GNU getopt to re-initialize. */ + while ((optc = getopt_long (argc, argv, "+iu:0", longopts, NULL)) != -1) + if (optc == 'u' && unsetenv (optarg)) + error (EXIT_CANCELED, errno, _("cannot unset %s"), quote (optarg)); + + if (optind < argc && STREQ (argv[optind], "-")) + ++optind; + + char *eq; + while (optind < argc && (eq = strchr (argv[optind], '='))) + { + if (putenv (argv[optind])) + { + *eq = '\0'; + error (EXIT_CANCELED, errno, _("cannot set %s"), + quote (argv[optind])); + } + optind++; + } + + /* If no program is specified, print the environment and exit. */ + if (argc <= optind) + { + char *const *e = environ; + while (*e) + printf ("%s%c", *e++, opt_nul_terminate_output ? '\0' : '\n'); + exit (EXIT_SUCCESS); + } + + if (opt_nul_terminate_output) + { + error (0, errno, _("cannot specify --null (-0) with command")); + usage (EXIT_CANCELED); + } + + execvp (argv[optind], &argv[optind]); + + { + int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE); + error (0, errno, "%s", argv[optind]); + exit (exit_status); + } +} |